Some implicit conversions are okay, like type promotion from int to double. Some type coercions are fraught, like char to int or back again. I agree that array decay to pointer could be explicit, and pointers shouldn't cast to arrays.
implicit int to double is really, really bad! it can silently truncate - double can only store 53 bits integers so for large integers the result will not be an integer!
in general, lossy conversions should never, ever be implicit
I would instead say int should be guaranteed to fit in a double. I feel like there's no reason to introduce a pitfall in > 99.999% of use cases just because there might be some obscure architecture where int is 64-bit and its programmers cannot be bothered with the extra keystroke for 'long'.
